Did it not come with directions? If it's like the slide my grandkids use it's a vinyl sheet on which you run water. I can tell you that if you leave it on the ground, the grass will turn yellow and eventually die. I never dried it off; just loosely rolled it up and set it on my patio to dry.
I googled this and learned that one family leaves the blower on to let it dry and then rolls it up and puts it in a plastic tub. Said it was easy to manage. I suggest that you don't have to take it down at the end of the day if you're not concerned about the lawn. If you are you could just move it every other day or so without drying it out.
http://www.walmart.com/ip/Banzai-Double-Cannon-Blast-Wate...
There were other sites listed when I googled but I didn't look at them. This seemed to answer your question.